1. Field of the Invention
This invention relates to a lubricant composition containing an alkoxylated amine salt of hydrocarbylsulfonic acid and its use to reduce friction and improve fuel economy in an internal combustion engine.
2. Description of the Related Art
There are many instances, as is well known, particularly under "Boundary Lubrication" conditions where two rubbing surfaces must be lubricated, or otherwise protected, so as to prevent wear and to insure continued movement. Moreover, where, as in most cases, friction between the two surfaces will increase the power required to effect movement and where the movement is an integral part of an energy conversion system, it is most desirable to effect the lubrication in a manner which will minimize this friction. As is also well known, both wear and friction can be reduced, with various degrees of success, through the addition of a suitable additive or combination thereof, to a natural or synthetic lubricant. Similarly, continued movement can be insured, again with varying degrees of success, through the addition of one or more appropriate additives.
The primary oil additive for the past 40 years for providing antiwear and antioxidant properties has been zinc dialkyldithiophosphate (ZDDP). Oil formulations containing ZDDP, however, require friction modifiers in order to reduce energy losses in overcoming friction. Such energy losses result in lower fuel economy. Moreover, oil additive packages containing ZDDP have environmental drawbacks. ZDDP adds to engine deposits which can lead to increased oil consumption and emissions. Moreover, ZDDP is not ash-free. Various ashless oil additive packages have been developed recently due to such environmental concerns.
It would be desirable to have a lubricating oil composition which provides excellent friction reducing, fuel economy properties and environmentally beneficial (less fuel, i.e., less exhaust emission) properties.